In some cases the logic order was not preserved properly when using `apply`. In particular this occurs when some logic is registered on a child of the root, followed by an apply to the root, followed by further logic registered on a child. In this case the final registered logic wound up running before the applied logic.
This happened because `FieldPathNode` for a child path was caching its `LogicNodeBuilder` at creation time. This meant that if the parent's `LogicNodeBuilder` changed (e.g., due to an `apply` call), the child would still be using the old one.
This commit fixes the issue by dynamically resolving the `LogicNodeBuilder` for a child path whenever it is accessed.
